Pile drivers

ABSTRACT

Cylinder stoppers and tower receiving blocks are automatically or self-operatively engaged or disengaged in the inventive pile drivers through cylinder operation so as to press a pile and to drop the monkey to apply its impact force to a pile provided that the pressing is inappropriate, and in some cases, this force is combined with a rotary excavating force of an earth auger to expedite quick and sure pile driving operation, e.g. of a precast pile.

United States Patent 11 1 1111 3,869,003 Yamada et al. 5] Mar. 4, 1975 PILE DRIVERS 2,655.006 /1953 Hoen 173/43 3,216,511 11/1965 Ladd et a1 173/22 X 175] lnvemms- Yamada, Ham, 3,232,360 2/1966 DiCkEIISOll 175/171 both of T y Kaname Nakayama, 3,447,613 6/1969 Lisenby 173/86 Funabashl, all of Japan 3,526,283 9/1970 HOI'SikeiIEr et a1... 173/126 x 3,568,571 3 1971 H ..91405 X [73] Assigneez Sanwa Klzal Kabushlkl Kaisha, 3.576218 45]! gg l I i i II73/46 Japan 3.685.301 8/1972 HeaCOX 6l/53.5 [22] Filed: Dec. 26, 1972 [21] APPL 318,543 Primary Examiner-Ernest R. Purser Assistant Examiner-William F. Pate, 111 Attorne A em, or FirmTab T. Thein [30] Foreign Application Priority Data y g Dec. 25, 1971 Japan 47-1062 Apr. 13. 1972 Japan 47-42895 ABSTRACT [52] U S CI 175/171 61/53 5 l73/28 Cylinder stoppers and tower receiving blocks are auto- 4/29 554/93 matically or self-operatively engaged or disengaged in [51] Int Cl Eozb "H44 the inventive pile drivers through cylinder operation [58] Field 61 Search 254/2912 31' 61/535 f Press a We 1 '9 the i 61/72 2 175/171 1 l73/l its impact force to a pile provided that the pressing is 138 b inappropriate, and in some cases, this force is combined with a rotary excavating force of an earth auger [56] References Cited to expedite quick and sure pile driving operation, e.g.

'1 UNITED STATES PATENTS a precast e 42.038 3/1864 Wood 173/113 8 Claims, 10 Drawing Figures PAIENIEWR 41915 4 saw u g g FIG. 4A

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min I 4 I Q Til I430 IIII PILE DRIVERS This invention relates to pile driving apparatus.

Heretofore, for driving precast piles into the ground, there have been popularly used percussion or striking devices such as Diesel-type pile hammers whereby holes are beforehand drilled in the ground and then the piles are driven into said holes. However the percussion devices such as Diesel pile hammers would produce excess noise and vibration, and would also cause contamination of the air owing to the exhaust gases.

Further if the driving operation is performed in a hard ground, the pile might break or become deformed due to the strong percussion force. On the other hand, according to the devices whereby holes are beforehand drilled in the ground and then the piles driven into the holes, the hole walls would often crumble during the piling operation, making it difficult to carry on the pile driving.

Therefore, in order to prevent such crumbling of the hole walls, particularly in a loose or soft ground, bentonite solution would be charged into the hole before driving a pile thereinto. However, although such measures can indeed prevent the crumbling of the hole walls, there arises a new problem concerning the disposal of sediments and water, resulting in elevated costs and considerable time required for the operation because of its increased and additional steps.

Further, according to this method, sure-footing is required for stabilizing the settlement of the piles that have been driven, and this necessitates the preparation of a heavy object as used to apply percussion.

In order to avoid these inconveniences, there has re cently been employed a system according to which, in case of driving hollow concrete piles or steel-pipe piles into the ground, an auger provided with a continuous screw is fitted in the hollow portion of the pile, whereby to excavate the ground beneath the pile while simultaneously forcing down the latter by a pressure device.

This system, although highly appraised for its lack of noise and vibration-free effect, still has the drawbacks that the pile settling speed is low because this depends solely on the pressure applied by a pressing device, and that the sure-footing work is required after the pile has been driven, necessitating the preparation of a heavy object for providing the percussion.

An object of the present invention is to provide a pile driving device having high operability and excavating performance.

It is another object of the invention to provide a device which not only greatly expedites the driving or settling of the piles but also allows easy detection or checking of the supporting capability of the pile.

It is still another object of the present invention to provide a piling mechanism whereby the dropping impact of the monkey can be conveyed to the pile without producing noise.

It is yet another object to further improve the piledriving performance of an earth auger with the percussion of the monkey or the pressing-in force of the cylinders.

A further object ofthe present invention is to provide a piling device which is simple in structure and easy in opcration.

An additional object ofthe present invention is to obtain a machine which is capable of performing the pile driving operation in one step and with a single machine.

erations, is conveyed to the pile without producing noise.

Further, according to another feature of the present invention, the continuous settling of the piles is attained by alternately using these operations and the driving force of the earth auger.

Other objects and many of the attendant advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description, when considered with the accompanying drawings, wherein FIG. 1 is a front elevation of an exemplary pile driver i embodying the present invention;

FIG. 2 is an enlarged partial front view of the princi pal parts of the pile driver of FIG. 1;

FIG. 3 is a sectional view taken along the line III III of FIG. 2;

FIGS. 4A to 4D are schematic illustrations showing the cyclic pressure cylinder operations in a step-by-step manner (applicable to both pile driver embodiments, namely those illustrated in FIGS. 1, 2 and 3, as well as 5, 6 and 7);

FIG. 5 is a front elevation of another embodiment of the present invention, otherwise similar to FIG. 1;

FIG. 6 is an enlarged partial front view of the pile driver of FIG. 5, otherwise similar to FIG. 2; and

FIG. 7 is a sectional view taken along the line VII VII of FIG. 6.

Referring now to FIG. 1, in respect of the first exemplary embodiment, it will be seen that a tower structure T (or leader mast) is erected upright on the ground G with a lower tower part being coupled to a catching fork F of a crawler or base machine I, and with an upper part being supported sidewise by a stay'rod 2 extending upwardly aslant from said crawler so that tower T can be either positioned upright as shown or inclined at any desired angle, by suitably adjusting rod 2.

As will also be seen, percussion means A for a precast pile P is suspended from the top of tower T by means of a wire W. The latter is extended from a winch 3 on crawler 1 and passed around sheaves 4 atop tower T and connected to a sheave 5 provided at the top of percussion means A so that the latter can be moved up and down by operating winch 3.

As shown in FIG. 2, percussion means A consists of a monkey 6 and a pair of hydraulic cylinders 7, 7a mounted therebelow. Monkey 6 has outside plates 8, 8a which are provided with rollers or guide elements 10, 10a engageable with respective guide frames or rails 9, 9a of tower T, better shown in FIG. 3, whereby monkey 6 can slidingly move up and down.

At the upper side of monkey 6 are provided stopper brackets 12, 12a on which stoppers 11, 11a are swingably mounted about respective supporting pins 13, 130. These stoppers 11, are arranged such that they are automatically swung outwardly by their own weights so that when the pile P is driven downward by the operation of cylinders 7, 7a, the upper faces of stoppers 11, 11a engage the corresponding lower faces of either pair of reaction-receiving brackets 14, 14a, 141, 141a, 142, 142a or 143, 143a which are arranged at suitable intervals vertically along tower T as shown.

According to a special feature of the invention, the bracket elements 14 143a are preferably trapezoidal in shape.

When percussion means A is hoisted up, stopppers 11, 110 are turned inwardly to the positions where they stay away from the passages of brackets 14, 14a and are secured at such positions by means of pins 15, 150 (see the dot-dash alternative positions shown in FIG. 2).

Mounted below monkey 6 are rams 16, 16a of respective cylinders 7, 7a, which are detachably secured at their bottom ends to a cap 17 fitted atop pile P.

As shown in FIGS. 4A to 4D, each cylinder (of which 7 is shown although the description understandably also applies to 70 and the associated elements) is formed with an upper charging-discharging port 18, a lower charging-discharging port 19 and a largediameter discharge port 20, and these ports are connected to conventional operative units through respective hoses (not shown); In the hoses connected to ports 19 and 20 check valves are preferably provided.

It is to be noted that lower port 19 is provided at a location slightly upward from the bottom of cylinder 7, and discharge port 20 is provided further upwardly than port 19, so that when a piston 21 of ram 16 (or 16a) drops, the fluid below port 20 will be trapped in the space between the bottom end of piston 21 and the inside bottom face of cylinder 7, as shown in FIG. 4D, to serve as a buffer medium, in order to avoid percussion sound.

In operation of this device, first cap 17 is fitted atop precast pile P and coupled to the bottom ends of cylinders 7, 7a, thus freeing the wires W. Then, in case the pile is driven into the ground which has beforehand been excavated by an auger or other like means, or into a comparatively soft ground, the large-diameter discharge ports 20, in cylinders 7, 7a are closed by the respective check valves, allowing the fluid to be forced out from lower ports 19 while discharging the fluid above pistons 21 from the upper ports 18 to thereby let the rains 16, 16a expand. At this time, stoppers 11, 11a on the top face of monkey 6 are kept inclined outwardly (solid-line showing in FIG. 2) so that they are caught by brackets 14, 14a of tower T to develop a reaction force which acts to force down pile P.

When the pile has dropped a distance equal to the stroke of cylinders 7, 7a, the operating fluid is forced out from upper ports 18 and at the same time the fluid below pistons 21 is discharged from the lower ports 19 to let rams 16, 16a retract to move down monkey 6. Then, when the operating fluid is fed again into cylinders 7, 7a, to let rams 16, 16a expand, stoppers 11, 11a are caught by the next pair of reaction-receiving brackets 141, 141a to develop a force acting to press down pile P, thus allowing the latter to begin further settling down.

The above-said operation is repeated until pile P is driven sufficiently into the ground. Thus, since stoppers 11,110 and brackets 141, 141a of tower T are automatically engaged and disengaged only through operation of the hydraulic cylinders, continuous and effec tive pile driving is performed.

In case the pile cannot be satisfactorily sunk only with the pressing force of the cylinders, owing to friction with the surrounding soil, obstacles in the ground or the like, the percussive impact force of monkey 6 is utilized. In this case, the following operations are conducted.

First, as shown in FIGS. 4A and 4B, pressure fluid is supplied from lower port 19 in cylinder 7 (and of course 7a, as explained before) to push up ram 16 (and 16a). During this time, port 20 is kept closed, and stoppers 11, Ila are turned inwardly and secured to respective brackets 12, 12a by means of pins 15, 15a.

Then port 20 is opened and port 19 is closed to supply fluid from port 18. This causes the fluid in the cylinder to be instantaneously discharged from port 20, owing to the weight of monkey 6, urging the latter to drop rapidly.

When piston 21 reaches its position below cylinder 7, port 20 is closed by the piston so that the fluid, unable to escape in any direction, is trapped between the bottom end of piston 21 and the inside bottom face of cyl inder 7, to play the role of a buffering medium to avoid metal-to-metal percussion sound which may otherwise be caused by impingment between the piston and the bottom face of the cylinder. Thus, the impact force developed by the dropping of monkey 6 can be conveyed to pile P with no noise being produced.

After the pile has been driven to a certain depth into the ground, sure-footing is effected by utilizing the drop impact force of monkey 6 so as to stabilize the settling of the pile. It is also possible to detect the supporting force of the pile.

It should be understood of course that the operation described in the preceding paragraphs for cylinder 7 and the associated elements, ports and circuits also relates to the companion cylinder 7a, as mentioned before, and can readily be seen from the symmetrical arrangement shown in FIG. 2.

Upon completion of one pile driving operation, the connection between cylinders 7, 7a and cap 17 at the top of the pile is released, and then percussion means A is hoisted up by wire W.

Now another exemplary embodiment of the present invention is described with particular reference to FIGS. 5 to 7, substantially similar to the respective described counterpart views 1 to 3. This embodiment has substantially the same structural mechanisms and parts as the preceding embodiment, and these are indicated with the same reference numerals except a few that will be explained hereunder.

It should be understood that the first embodiment is particularly suitable for precast piles P while the second embodiment, to be described hereinafter, is best suited for hollow piles as shown in FIGS. 5 and 6 at P'.

With further reference to FIG. 5, tower T, having its lower part coupled to base machine or crawler 1, is supported sidewise by stay rod 2 such that the tower may be inclined at a desired angle, and an earth auger B is suspended from tower T by means of wire W. The latter is again extended from winch 3 on crawler 1, passed around sheaves 4 atop tower T and connected to sheave 5, this time on earth auger B, so that the latter can be moved up and down by operating winch 3.

Earth auger B, as shown in FIG. 6, includes an auger driving unit 22 having a motor M housed in a holder 220, with an auger screw 23 connected to the output shaft of the gear assembly, and a monkey 6 or some other suitable block is mounted as a press-in (or percussion) means C. 1

There is also provided an excavating head 27 at the bottom end of an auger screw shaft 230, which is joined to an output shaft 24- of driving unit 22 by means of couplings 25, 26. Numeral 28 designates a pair of sheave holding brackets provided on the upper face of unit holder 22a, with sheave 5 being attached to brackets 28 by means of a pin 29, while 30, 30a indicate supporting monkey detents which will be described later.

Press-in means C consists of monkey 6', as mentioned, by which unit holder 22a is slidably surrounded, and cylinders 7, 7a mounted at the bottom of said monkey. In the inside of the former are provided a suitable number of guide rollers 32, 32a engaged with respective guide rails 31, 31a provided on opposed sides of holder 22a. Earlier'mentioned rollers 10, 10a, engaged with guide frames 9, 9a of tower T, are provided on outside plates 8, 8a of monkey 6.

At both top ends of monkey 6' are provided stopper brackets I2, I211 on which stoppers Ill, 11a are swingably secured by pins I3, 13a. The arrangement, function and effect of these stoppers are the same as those of the preceding embodiment.

In case press'in means C is used to merely perform its pressing-in function, monkey 6' is only required to serve as a cylinder receiver, and hence in such a case the monkey may be substituted by some other simpler object. But, for simplicity of explanation, all available means are represented by a monkey in the following discussion.

From the previous and the following description it should be clear that parts 18, I9, and 21, fully described in connection with FIGS. 4A through 4D, are also part of the second embodiment (FIGS. 5 through 7) although not shown specifically therein. By way of summary it might be added at this point that elements I through 21 (some also having right-hand counterparts, such as cylinder pair 7, 7a on the left and right sides, respectively) have been described in connection with the first embodiment, most of the parts being also applicable to the second, while elements 22 through 32 only apply to the second embodiment.

Now the mechanism of press-in means C is described in detail with reference to FIGS. 6 and 7. Cylinders 7, 7a below monkey 6 have their respective rams 16, 16a secured to the underside of said monkey, with the bottom ends of said cylinders being detachably joined to cap I7 at the top of hollow pile P to be driven into the ground. These cylinders are completely the same as those used in the preceding embodiment. Namely, as apparent from FIGS. 4A through 4D, they have upper charging-discharging ports I8, lower charging discharging ports I9 and discharging ports 20 with an enlarged diameter, all of these ports being connected to the operating units by respective hoses. Check valves may again be provided in ports 19 and 20.

Also, as in the case of the preceding embodiment, each lower port 19 is provided slightly upwardly from the bottom face of cylinder 7, and port 20 is provided further (but only slightly) upwardly than port I9, so that when piston 21 of ram I6 (and of course of 16a) drops, the fluid below port 20 will be trapped between the bottom end of piston 2I and the inside bottom face of cylinder 7, as shown in FIG. 4D, so as to play the role of a buffer medium, to avoid generation of percussion sound. The same again applied to cylinder 7a.

In operation of this embodiment, first auger screw 23 is inserted into the interior of hollow pile P which is mounted at its top end with cap 17, and then this auger screw is connected to shaft 24 of auger driving unit 22, and cap I7 is joined to the bottom ends of cylinders 7, 7a as shown in FIG. 6. Then motor M is operated to rotate screw 23 to let earth auger B move downwards.

Aided by the excavating and earth-moving actions of auger screw 23, pile P gradually sinks into the ground under the load given by its own weight plus the weight of monkey 6'. In case the pile does not settle down smoothly owing to large friction with the surrounding earth, ports 20 of cylinders 7, 7a are closed by the respective check valves, causing the fluid to be forced out from ports 19, and at the same time the fluid above pistons 21 is discharged from ports 18 to let rams I6, 16a expand. During this time, stoppers 11, 11a at the top of monkey 6' are kept slanted outwardly so that they are checked by brackets 14, 14a in tower T to develop a reactive force, thereby to force pile P downwardly, in the same manner as in the preceding embodiment.

When the pile has sunk by the length of the cylinder stroke, the fluid is forced out from ports 18 while discharging the same below pistons 21 from ports l9 to let rams I6, I6a contract so as accordingly to lower monkey 6, and then when the rams are again expanded in the manner described before, stoppers 11, Ila are caught by the next pair of reaction-receiving blocks 141, I410 to urge additional sinking movement of the pile. The above operation is repeated to effect continuous settling of the pile. This is of course aided or performed by the further brackets 142, 143a described earlier.

In case it is found that the pile is too hard to let is sink only with the pressing force of the cylinders, owing to large friction with the surrounding soil or some obstacles in the ground, the monkey is dropped by following the same procedure as described before, thereby to percussively force the pile down into the ground, and stoppers 11, 11a are turned inwardly and located by pins 15, 150.

When the pile has been driven to a certain predetermined depth, sure-footing is performed by utilizing the impact force produced by the dropped monkey. It is.

here possible to establish the pile supporting force.

Upon completion of each pile driving operation, cylinders 7, 7a are disconnected from cap 17, and 11a are turned inwardly and locked by pins 15, 15a, and then earth auger B is hoisted up by wire W. With the rise of the earth auger, monkey 6 is also lifted up, being carried on corresponding supporting detent pieces 30, 30a provided protrudingly on the sides of auger driving unit holder 220.

It should be understood, of course, that the foregoing disclosure relates only to preferred embodiments of the invention, and that it is intended to cover all changes and modifications of the examples described which do not constitute departures from the spirit and scope of the invention.

What we claim is:

I. A pile driving apparatus comprising, in combination: a tower erected on a base, adapted to support a hollow pile to be driven into the ground; a plurality of reaction-receiving elements arranged in pairs vertically at suitable intervals along the length of said tower; a

monkey slidably suspended from said tower and having stoppers attached thereto and successively engageable with said pairs of elements; said monkey constituting part of press-in means and being in the form of a framework with a central opening; an assembly support slidably suspended from said framework; actuating hydraulic cylinders disposed below said monkey for driving the pile into the ground by the pressing force provided by said cylinders; and earth auger means including an auger screw insertable into the hollow pile, whereby the latter can be driven into the ground by the combined pressing force provided by said cylinders, as aforesaid, and the excavating force of said screw.

2. The pile driving apparatus as defined in claim 1, wherein said hydraulic cylinders include buffer means for avoiding the generation of percussion sound when the impact force of the dropping monkey is received by said cylinders.

3. The pile driving apparatus as defined in claim 1, wherein said reaction-receiving elements are substantially trapezoidal in shape.

4. The pile driving apparatus as defined in claim 1, wherein said monkey has outer'side plates carrying guide elements, the latter for engaging rail means disposed along at least a portion of said tower for sliding displacement of said monkey therealong.

5. The pile driving apparatus as defined in claim I, wherein said earth auger further includes an excavating head at the end of said screw, and means for rotating the latter together with said head.

6. The pile driving apparatus as defined in claim 5, further comprising coupling means between said rotating means and said screw.

7. The pile driving apparatus as defined in claim I, wherein said framework has on its inside further guide elements for engaging further rail means disposed along at least a portion of said assembly support.

8. The pile driving apparatus as defined in claim 7, wherein said assembly support has at least one lateral supporting detent adapted to be engaged by and during the upward movement of said earth auger means. 

1. A pile driving apparatus comprising, in combination: a tower erected on a base, adapted to support a hollow pile to be driven into the ground; a plurality of reaction-receiving elements arranged in pairs vertically at suitable intervals along the length of said tower; a monkey slidably suspended from said tower and having stoppers attached thereto and successively engageable with said pairs of elements; said monkey constituting part of press-in means and being in the form of a framework with a central opening; an assembly support slidably suspended from said framework; actuating hydraulic cylinders disposed below said monkey for driving the pile into the ground by the pressing force provided by said cylinders; and earth auger means including an auger screw insertable into the hollow pile, whereby the latter can be driven into the ground by the combined pressing force provided by said cylinders, as aforesaid, and the excavating force of said screw.
 2. The pile driving apparatus as defined in claim 1, wherein said hydraulic cylinders include buffer means for avoiding the generation of percussion sound when the impact force of the dropping monkey is received by said cylinders.
 3. The pile driving apparatus as defined in claim 1, wherein said reaction-receiving elements are substantially trapezoidal in shape.
 4. The pile driving apparatus as defined in claim 1, wherein said monkey has outer side plates carrying guide elements, the latter for engaging rail means disposed along at least a portion of said tower for sliding displacement of said monkey therealong.
 5. The pile driving apparatus as defined in claim 1, wherein said earth auger further includes an excavating head at the end of said screw, and means for rotating the latter together with said head.
 6. The pile driving apparatus as defined in claim 5, further comprising coupling means between said rotating means and said screw.
 7. The pile driving appaRatus as defined in claim 1, wherein said framework has on its inside further guide elements for engaging further rail means disposed along at least a portion of said assembly support.
 8. The pile driving apparatus as defined in claim 7, wherein said assembly support has at least one lateral supporting detent adapted to be engaged by and during the upward movement of said earth auger means. 